Rupa ji, the incidents in question belong the early solar system, 4.5 billion years ago. Much like modern scientists who use observations and measurements to postulate models about the cosmos, our Rishis probably used contemplation, meditative states of mind, and had access to unknown means of knowledge to postulate models embedded in stories using difficult metaphors. We don't know who the rishis were, but their stories are recounted in different Puranas. Dating the Puranas has been done by West using linguistics and latest recensions, but ignoring the astronomy. Puranas could have been a "live document", with many generations adding to the corpus of works. My feeling - based on astronomy from supporting texts - is these works are at least 3000 BCE, if not earlier.